Apparatus for manufacturing vehicle wiring harnesses



Dec. 28, 1965 R. o. SCOFIELD, sR., ET AL 3,226,278

APPARATUS FOR MANUFACTURING VEHICLE WIRING HARNESSES Filed Sept. 28, 1961 FLOW INDICATOR 40 I AIR HEATER if 1/ .46 9

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INVENTORS ROBERT O. SCOFIELD 6R.

RICHARD M. HESS THEIR ATTORNEY United States Patent C) T APPARATUS FOR MA UFACTURING VEHICLE WIRING HARNESSES Robert O. Scofield, Sr., and Richard M. Hess, both of 7 Warren, Ohio, assiguors to General Motors Corporation, Detroit, Mich, a corporation of Delaware Filed Sept. 28, 1961, Ser. No. 141,519 1 Claim. ((11. 156-497) This invention relates to making of vehicle wiring harnesses and, more particularly, to a process and system for producing flat or generally rectangular conductor harness means for use in motor vehicles and the like.

An object of this invention is to provide a new and improved process and system of manufacturing wiring harness means into fiat rectangular-shaped structure by use of an air heater and hot air jets to enhance control of adherence and to minimize handling difliculty of materials.

Another object of this invention is to provide for making of wiring harnesses by use of only hot fluid medium such as hot air in a specifically directed jet stream to effect softening of plastic insulating material along parallel though flattened electrical conductors which are subjected to lateral force until cooled while being moved at a uniform rate of speed which in combination with the temperature of air jets and pressure applied can give a decided degree of adhesion.

Another object of this invention is to provide a system for making wiring harness means utilizing apparatus to include a source of fluid medium such as air supplied under pressure subject to passage through a reducing valve means that controls the amount of flow thereof as indicated on a flow indicator prior to advance through confines of an electrically energized heater means to a degree of temperature controlled by a variable transformer and indicated by a wattmeter before passed by a valve to direct heated air either to discharge as well as to a longitudinally perforated jet tube that directs the heated air into a location between insulated flat conductors to be joined by heated thermoplastic covering of insulating material solely by use of surface softening thereof by heated air having temperature thereof controlled according to volume of air and wattage power input to the heater means.

A further object of this invention is .to provide for manufacture of wiring harness means by an air-weld process including steps of first, separating fiat insulated rectangular conductor means by an unheated dividing pinlike projection of sufiicient size to assure formation of access space between the insulated conductor means, jetting heated air under pressure into this access space to soften exposed edges of insulated conductor means to a tacky and plastic condition short of melting flow, and forcing the insulated conductor means together in sealed relation under opposing lateral pressure maintained for a predetermined length of time until insulating material is fused into a weld and cooled free of conductor buckling.

Another object of this invention is to provide a new approach to solve problems of lack of space as to wiring harness means for automotive and vehicle wiring by fiatening conductor material into a tape-like rectangular configuration, covering the flattened conductor material with thermoplastic insulating material, and joining in a parallel manner the flattened conductor material representing differing gauges of current-carrying capacity such that narrow space or very limited passages between vehicle body components can be fitted with wiring harness means.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings wherein preferred embodiments of the present invention are clearly shown.

3,226,278 Patented Dec. 28, 1965 In the drawings:

FIGURE 1 is a diagrammatic representation of a system of wiring harness manufacture in accordance with the present invention.

FIGURE 2 is a perspective View to illustrate progressive operation and wire harness processing in accordance with the system of FIGURE 1.

In recent years motor vehicle manufacturers have provided an increase in electrical components and accessory devices requiring electrical energization such that wiring harness means formed by grouping and bundling a plurality of rounded conductors can require a substantial opening or passage between various motor vehicle components such as body panels and the like. Also, there has been a trend toward reduction of external dimensions of motor vehicles requiring thickness of doors and panel coverings to be reduced so as to attempt to maintain interior roominess and seating capacity as well as suflicient luggage space. Quite often a problem can arise in placement of bundled round conductor means through a limited and narrow space such as between body or Wall panels and upholstery for seating as well as for covering such panels. Systems and processing of conductor means provided with insulating coverings can be made to provide wiring harness means substantially rectangular in shape and flattened to fit efiiciently and properly in limited and narrow space on certain motor vehicle locations. It is to be noted where adequate space is available a motor vehicle can be provided with certain connector attachments as well as limited members of rounded conductors though a new approach is necessary to provide for transfer of electrical energization in spite of limited and narrow space.

FIGURE 1 illustrates a source 10 of fluid medium such as air under pressure transferred by a conduit or pipeline 11 and passed through a reducing valve means 12 which controls the amount of air flow permitted to proceed through a further conduit or line 13 that can be provided with a flow indicator means 14. The system or apparatus further includes a continuing supply line 15 suitably fitted in sealing engagement with one side of a heater means generally indicated by numeral 16 having a housing 17 having a predetermined space in the confines thereof in which suitable rheostat or resistance means 18 can be located. This resistance means can be in the form of a zigzag grid to increase surface area around which the fluid medium or air under pressure can flow and pass to an exit line 19. For observation by an operator there is a temperature indicator 20 between the exit line 19 and a further conduit or pipe connection 21 which communicates by way of a multi-passage valve means 22 with either a discharge line 23 or a final supply line 24 that terminates with a probe-like jet means 25 having a plurality of longitudinally aligned passages 26 peripherally along one side thereof.

A suitable pair of energizing leads 127 and 128 can be provided and connected to each of opposites sides of the resistance or grid-like rheostat means 18 and a power measuring device such as a wattmeter 129 which can be observed by the operator who can manipulate and control energy supplied to the grid-like resistance means 18 by adjusting a slideable end or movable connection of the lead 128 to a variable source of power or transformer means 130 energized by lines 131 and 132.

Referring more particularly to the illustration of FIG- URE 2, there is an enlarged illustration of the final supply line 24 and jet means 25 having the passages or openings 26 longitudinally aligned along one side thereof. These passages 26 are located longitudinally in alignment with each other and are spaced laterally to one side of a divider probe or pin-like unheated projection 27 suitably anchored to a base 28. It is to be noted that this divider projection 27 is totally unheated but has a predetermined width to form an access space 30 which is substantially V-shaped within lateral limits defined by first and second flattened conductor means 31 and 32 having a thermoplastic insulating covering means 33 and 34, respectively, carried thereon. Only hot air under pressure is jetted through the passages 26 in the direction of arrows 35 to locations along adjacent though spaced narrow edges 37 and 38 of the thermoplastic insulating covering means 33 and 34, respectively. This hot air as represented by arrows 35 is directed specifically in a jet stream to effect softening of the plastic insulating material along the edges 37-38 of the substantially parallel though flattened electrical conductors finally to emerge in a generally rectangular conductor harness means generally indicated by numeral 40 in FIGURE 2. Only a fluid medium such as air heated and under pressure is directed to the edges 37 and 38 of the insulating material which is completely free of any adhesives which would be messy and difficult to handle and the probe-like projection 27 is also totally unheated so as to avoid accumulation of melted plastic material thereon as would occur if this projection 27 were also heated. There is a greater and more effective control of transfer of heat to the edges 37-38 by the hot air jet streams as indicated by arrows 35 and thus, a critical maintenance of only a tacky condition of the thermoplastic insulating material can be maintained short of any melting and undesirable flow of the insulating material which would thus become irregular and result in improper adherence of the insulating coverings 33-34 to each other so as to form the substantially rectangular wiring harness means 40 including at least two and further substantially parallel conductors such as 31 and 32 which can have differing cross-sectional area or gauging so as to accommodate various energizing currents for various electrical de vices having differing power requirements. The substantially triangular access space 30 is defined within limits of a base formed by the width of the probe-like projection 27 and the considerably longer edges 37-38 forming an acute angle therebetween as an isoceles triangle. It is to be understood that several such access spaces can be provided in laterally spaced positions subject to parallel location of several jet means similar to that indicated by reference numeral 25 to make a rectangular wiring harness means having three and more substantially parallel insulated flattened conductor means joined so as to have only a very thin cross section though having a plurality of energizing paths therewith.

Illustrated schematically in FIGURE 2 there are actuators 41 and 42 having cylindrical housings with piston means 43 and 44, respectively, reciprocable therein under urging of fluid medium under pressure. These pistons 43 and 44 can be carried by reciprocable rods 45 and 46, respectively, which can be attached to opposing pressure devices 47 and 48 laterally movable relative to each other to compress and pressure the edges 37-38 into a predetermined degree of adhesion and sticking contiguous to each other. Another actuator, not shown, can cause movement of a further pressure device or mandrel 49. These pressure devices 47, 48 and 49 can operate on a machine having a base such as 28 and suitable conduits can be provided for each of the actuators for effecting to and fro movement of the pistons therein. A suitable fluid medium would be air under pressure which could be obtained from the air supply shown in FIGURE 1. An air-weld or fusion juncture line 50 is progressively formed by joining of the edges 37-38 under pressure and an operator can carefully control the temperature and pressure of air supplied by way of the passages 26 in the jet means 25. The top pressure device 49 can be a roller geared for rotation and thereby supplementing control of feed of insulated rectangular conductor means to be joined in a flattened wiring harness means 40. In addition to having differing gauges of rectangularly cross-sectioned conductors 31 and 32, it is possible to provide color-coat- 4 ing for the insulating materials or coverings 33 and 3 so that the flattened wire harness means 40 can pass through narrow and limited space wherein rounded conductors and group or bundled insulated wires could not be fitted into place.

Use of the jet means 25 for supply of hot air by way of passages 26 requires considerably less heating and fuel or electric power than if the entire insulating covering were subjected to over-all heating in an oven in which there could be no limited edge heating while temperature of remaining insulating material and conductor material covered thereby is free of any substantial increase in temperature. Since the conductor means 31 and 32 as well as the majority of the insulating materials 33 and 34 is not subjected to such heating there is a quicker cooling and final bonding of the rectangular-shaped insulated conductor means so as to require a minimum of time during which opposing pressure devices force the insulated conductors together and seal them into a weld line.

The pressure of air can be effectively controlled by the reducing valve means 12 and the temperature of the heater means 16 can be effectively adjusted by an operator by way of the transformer means 130. The operator can observe the flow indicator means 14 as well as the wattmeter 129 and temperature indicator 20 and the valve means 22 can divert the heated air either to discharge by way of the line 23 or to the jet means 25 by way of the final supply line 24. Preferably the insulated rectangular conductor means are pulled through the jet stream of specifically directed hot air at a uniform speed which in combination with the control of the temperature of the air jets and the pressure applied can provide an accurate weld of adhesion of the insulating material in a plastic state free of undesirable melting and deformation thereof. Reference can be made to a copending application S.N. 141,483, Baer et a1. filed September 28, 1961, concerning further details of rectangular conductor harness means and attachments therefor.

The air-weld process of the present invention includes steps of first, separating flat insulated rectangular conductor means by the unheated divider projection 27 having suflicient width to assure formation of the access space 30 between the insulated conductor means. There is a step of jetting heated air under pressure into this access space to soften exposed edges 37-38 of the insulated conductor means to a tacky and plastic condition short of melting flow and finally a forcing and pressing together of the insulated conductor means in sealed relation at a uniform rate of movement under lateral pressure maintained for a predetermined length of time until insulating material is fused into a weld and cooled free of conductor buckling.

While the embodiments of the present invention herein disclosed constitute preferred forms, it is to be understood that other forms might be adopted.

What is claimed is as follows:

In an apparatus for the manufacture of a wiring harness means including plural flat conductors each having rectangularly shaped thermoplastic insulation in substantially coplanar relationship and united in edge-to-edge relationship by being passed in contact with a heated fluid pressure stream, the improvement which comprises a relatively flat surface base member for supporting at least two moving coplanar flat insulated conductors and including an elongated aperture extending through said base surface, a

fluid pressure jet means including orifices arranged in 1on gitudinal alignment and directing fluid pressure upwardly through said aperture along the underside of the plural;- insulated conductors to be joined at their edges, a nonheated dividing projection extending upwardly from one end of said base member surface and longitudinally aligned with orifices of said jet means for transversely separating .the conductors between adjacent narrow edges of thermoplastic insulating material, said dividing means engaging the thermoplastic insulation between the edges of the coplanar flat conductors defining a space therebetween prior to contact With the heated fluid stream of said jet means, means including a pair of parallel side portions and a roller intermediate said side portions and above said surface located at the other end of said base 5 surface and longitudinally aligned with both said projection and said jet means for simultaneously applying lateral pressure to the coplanar flat insulated conductors and urging the flat conductors into a parallel and coplanar position causing a butt-juncture entirely of thermoplastic insulating material from that heated by said jet means along the insulation edges, and a temperature control means for regulating the heat from said jet means to cause the insulation to become a plastic condition short of melting flow and to fuse against each other along the buttjuncture When moved at a substantially uniform rate.

References Cited by the Examiner UNITED STATES PATENTS 2,587,422 2/1952 Wills l56-497 2,749,261 6/1956 Harclison 15647 10 2,997,098 8/1961 Riese et a1 156497 EARL M. BERGERT, Primary Examiner, 

